Piston ring compressor



y 1940- L. B. MILLER ,208,136

PISTON RING COMPRESSOR Filed Aug. 7, 1959 v Ha I I Leon flMz'ZZer h if TTORNEY.

Patented July 16, 1940 PATENT OFFICE 'PIS'I'ON RING COMPRESSOR Leon B. Miller, mm'n. Y.

Application Augusta, 1939, Serial No. 288.862

3 Claims. (01. 2946.4)

This invention relates to piston ring compressors, and has for its principal objects the production of piston ring compressors of an improved construction, which not only facilitates their employment with an exceptionally wide variety of piston sizes, but which may be actually set, held in position and safely released to any desired extent, and which will operate uniformly over the entire range and compress all the rings I in a piston evenly, and retain them in their compressed position until they are safely inserted in the cylinder.

Another object of this invention is to produce an improved type of piston ring compressor v1E5 wherein means are provided for assuring not only g a uniform compression of rings into the grooves of a piston and exact operation of the device, but wherein the operation of the device inay be minutely controlled, both while the device is being applied to its intended work and when being released. g The foregoing and a number of .other objects and important advantages will become more fully apparent from the. ensuing description of the 2g accompanying drawing, which, although illustrating specific, presently preferred form of my invention, are by no means intended to limit me to that disclosure, and in which Fig. 1 is a top view of my device. n Fig. 2 is an elevation thereof in one of its forms. I

Fig.3 is a partial vertical cross sectional view through the operating mechanism of my device, as illustrated in Fig. 2. i Fig.4 is a cross sectional view taken on line t-t of Fig. 2. I Fig. 5 is a cross sectional view, 5-5 of Fig. 2.

Fig. 6 is a partial elevation of a modified form of my device, and v Fig. 7 is a vertical cross sectional view of a modified form of the rotatable instrumentality employed in my device. Referring now more specifically to the drawing, numeral.l0 denotes a relatively broad spirally wound resilient piston compressing strip which is provided at its lower edge with a plurality of outwardly directed notches ll, intended to form stops for resting the strip against the edge of the cylinder wall, intd which the piston with the compressed ringsis intended to be inserted. By means of these notches or stops strip III is prevented from inadvertently slipping into the cylinder, while the strip portions between the spaced 55 notches serve as guides for the rings.

taken on line The free end III of the strip (see Fig. l.) is disposed at the interior of the substantially ringshaped spiral formed by the strip, while the other end III" of the strip constitutes the exterior end thereof. To this exterior end is permanently attached a mounting l2 by means of rivets or other suitable fastening elements indicated at l3. This mounting is in the form of a looped structure having an interior leg (4 and an ex-- terior leg l5, between which is held a stiifening' or reinforcing member I6 in the form of a spacer bar, as may be clearly seen from Fig. 3. Ex-

tending through the bar i are screws l1 and l8, the latter preferably provided with a wing nut l9; The looped portions of the structure are indicated at 20 and 20' which are swung about an operative instrumentality rotatable within the loops.

This rotatable instrumentality constitutes for all practical purposes a one-piece'hollow or tubular member 22, provided at its upper end with g a socket 23 for the reception of a key or wrench 24, indicated in Fig. 2 This wrench and socket are made preferably of square cross sections. Tubular member 22 is provided with end flanges 25 and 26, and between the flanges are arranged ratchet wheels 21, 28 and 29. Ratchet wheels 21 and 28 have their teeth arranged preferably in the same direction, while the ratchet teeth of wheel 29 are set in opposite direction to the teeth of wheels 21 and; 28. y

In the construction shown in Figs. '2 and 3 I have shown spacers 30 and 30' arranged between vflange 25 and. ratchet wheel 21, and between flange 26 and ratchet wheel 28, respectively. I also provide in this construction spacers 3| and 3| between ratchet wheels 21 and 29, and between ratchet wheels 28' and 29, respectively. Spacers, as well as flanges 25 and 26, and also all three ratchet wheels are permanently united with tubu- 40 lar member 22 by being either secured to the latter by shrinking them thereon, or by means of spot welding, or in any other suitable way such as rivetingor the like. Inother words, the rotatable instrumentality lodged within loops 20 and'2l of mounting l2 represents essentially a one-piece member,

Secured by way of the outer two rivets l3, whereby mounting I 2 is united with a strip III, are the fixed ends of highly resilient, relatively 5 narrow and thin compression bands 32 8.111132. These bands are parallel to one another and are arranged at the extreme lower and upper edges of strip In. Their operative ends are secured within slots 33 and 33', which are cut through I8 is a detent plate 35, made of'resilient material,

and. which is provided with two outer spring detents or ratchets 36 and 36' and an interior detent 31. The outer detents are adapted to respectively engage ratchet wheels 21 and 28,'

while the interior detent 31 is intended to coop erate with central ratchet wheel 29.

In the full line position of plate 35, shown in j Fig. 2, detents 36 and 36' engage their respective ratchet wheels, while detent 31 clears ratchet wheel 29. While plate 35 is in this position, instrumentality 2! may be turned in clockwise direction, whereby compression bands 32 and 32' are being wound up. Through this operation strip I0 is being compressed or wound tight about a piston, and rings mounted in their respective piston grooves are-forced into the latter.

It is obvious that while detents 36 and 36' engage their respective ratchet wheels, the ratchet wheel arrangement for each of the bands 34 and 34' will prevent individually the unwinding of these bands.

In addition my invention contemplates that the teeth of the ratchet wheel be so designed that the tightening or winding up of the bands for each tooth length will correspond to a certain measured compression of piston-engaging strip l0. Furthermore the click produced by the detents successively engaging the teeth of the ratchets enables the operator-to determine by audible means the extent of dimensional changes of the compressed strip.

Detent plate 35, being provided with suitable adjusting slots 38 and 39, through which project screws i1 and I3, may be shifted within the range of these slots. The plate may be fastened in any desired position by wing nut l9, or any other suitable means.

ton-engaging strip l0, wing nut I9 is loosened and plate 35 is moved to the position indicated in broken lines in Fig. 2, in which position detents 33 and 36' release their respective ratchet wheels 21 and 28, while detent 31 will engage-ratchet wheel 29. Through this engagement between resilientdetent 31 and ratchet wheel 29 an ef-' fective braking action will be provided for too violent an unwinding of coils 34 .and 34, as ratchet, pawl or detent 31 is caused to forcibly glide over the teeth of ratchet wheel 29. The position of detent 31 is clearly indicated in Fig. 5, and the direction of unwinding of the bands is indicated ,by the arrow.

Another embodiment of my invention, and especially of thewinding arrangement of bands 32 and 32' and or mounting I2" is indicated in Fig. 6, wherein the central ratchet wheel is omitted, while ratchet wheels 21' and 23' are retained. Instead of splitting the looped formation mine manner shown in Figs. 2 and 3, the mod-. 'ified form shows a continuous, "one-piece loop 40 which engages the central portion of instrumentality 2i between ratchet wheels, 21 and 28'. The constructionof resilient detent plate 4| with its detents or ratchets 42 and 43 also is al-.

"-tered since the central ratchet is eliminated.

When it is desired ot release pis-.

' ratchet wheels 21 and 28', if so desired. Inasmuch as in the modified form of Fig. 6 the special braking arrangement is eliminated, the operator of this device will have to rely upon the internal friction between the layers of the coiledup bands 32 and 3 2" and a possible frictional engagement between the detents and the faces of the ratchet wheels. This modified form is designed for devices of a relatively small range, in other words, for devices which will serve a very limited variety of piston and piston ring sizes, whereas the device described in connection with Figs. 2 and 3 has an extremely wide range, and requires therefore some means of more positively braking the unwinding force of coiled ends 34 and 34' of the compression bands.

In Fig. '1 there is illustrated a modified form of the winding instrumentality wherein the entire structure, such as employed in Fig. 6, is shown to be-made of one piece, and wherein from the tubular portion 44 extend flanges 45 and 46, as well as ratchet wheels 41 and 48. This device is fabricated from drawn ratchet wheel stock, which is turned down to form the respective flanges and the recesses for accommodating band ends 34 and 34' and loop 40 of the mounting.

Operation In either one of the two modified forms illustrated the function of my device is substantially identical. When a piston with piston rings in its groovesis to be inserted into a cylinder, it is necessary to compress the piston rings so that they move into their respective grooves suflicient- 1y to permit the insertion of the ring-equipped piston into the cylinder cavity. This is accomplished byfplacing the partially expanded pistonengaging "strip l0 over the piston and operating winding instrumentality 2i by means of wrench 24in one direction, for instance in clockwise di-,

rection, whereby bands 32and 32 are caused to be wound up. Prior to winding up these bands the detent plate is set into operative engagement with the ratchet wheels so that when the winding takes place the bands are prevented from unwinding. When the bands are sumciently tightstrenuous, but mustbe sufllcient to hold the piston rings in the grooves during the insertion o the piston into the cylinder.

When the piston is inserted the piston ring" compressor is removed and may be released. This is preferably done in' first preventing the compression band from unwinding by immovabiyholding handle 24, shifting the detent plate so that either 'middle ratchet wheel 23 is engaged by its corresponding detent, in the construction shown in Figs. 2 and 3, or so that the detents of the exterior ratchet wheels will frictionally engage the faces of-the latter. The handle may then be released and the unwinding of the bands will be retarded by the braking action of either the central or the end ratchet wheels. This brak- 7 ing provision is rather important since it often ity.

spouse occurs that the rapid unwinding of the bands,

induced by the forceful expansion of strip l0,

may be so severe that it may break the anchored ends of the bands in their winding instrumental- Conclusion I While I am well aware of piston ring combands being parallel to one another and being so spaced that they uniformly engage the extreme edges of thestrip, a mounting flxedly secured to the outer end of the strip and forming a fixed anchorage for one end of the bands. band pressors of different designs and employing. ar--' rangements similarto those indicated in my disclosure, I have found that none of them compress their piston-engaging strip uniformly and especially at the extreme edges of the strip, and that instead of inducing the piston-engaging strip to assume a truly cylindrical form, the form of the strip becomes conical or otherwise out of shape and will not produce theintended function of uniformly engaging the entire surface of the piston. In order to produce a uniform compression of the piston rings it is important that the compression bands be mounted at the very edges of the piston-engaging strip, and that they are uniformly drawn or wound and that the bands are truly parallel to one another, since, otherwise a twisting of the strip ensues.- Such twisting of the piston-engaging strip loosens some of the rings and instead of facilitating the insertion of the piston into the cylinder this operation is made difiicult and often results in the breakage of the rings.

I, therefore, believe that I am the first who constructs a piston ring compressor with two parallel compression bands arranged at the very edges of the pistomengaging strip, and that I am the first who provides anefiective, positive braking arrangement which prevents the rapid unwinding of the compression bands and thereby winding means rotatably lodged in the mounting and engaging the other ends of the bands, said winding .means comprising a hollow structure having end fianges for guiding the outer edges of the bandsand ratchet wheels between the flanges for guiding the inner edges of the bands, and positivelatching means for engaging the ratchet wheels.

2. In a piston ring compressor, the combina tion with a relatively broad, resilient strip, wound spirally to a substantiallytrue cylindrical form and adapted to be maintained in that form at any-desireddiameter, for the reception and retention of any desired sizes of piston'rings; of a pair of windable, parallelly disposed compression bands encircling the extreme edges of the cylindrically'wound strip and adapted to vary the latters diameter while maintaining the strip in its true cylindrical form, band operating means sev cured to the outer end of thestrip and adapted possible damage to the device and to the operator. 1

means, and I, therefore, wish it to be understood that I reserve for myself the right to make changes and improvements in the construction of my invention, all within its broad scope as expressed in the annexed claims.

Iclaim: 1. In a piston ring compressor, a spirally to facilitate the simultaneous winding and unwinding of both bands under uniform tension, means for maintaining the bands parallel and in engagement with the extreme edges of the cylindrical form of the strip, means for positively controlling the operation of the bands provided with said operating means, said controlling means comprising ratchet arrangements for each band and including adjustable and releasable ratchets. 3

3. In a pistonring compressor, the combination with a spirally wound, resilient strip, adapted to always form a substantially true cylinder; of a pair of always parallelly maintained, simultaneously and uniformly windablecompression bands, adapted to-always engage the extreme edges of the cylindricaily formed strip, and releasable, positively controlled means for facilitating the simultaneous and uniform winding and unwinding operations of both bands to reduce and increase, respectively, the diameter of the cylinder formed by the strip, and for maintaining its true cylindrical shape, said controlled means comprising a shaft, a pair of guide means at the ends thereof, one for each compression band, for maintaining the bands in parallel, overwound, resilient piston engaging strip intended to always assume a. substantially true cylindrical shape, a pair of compression bands designed to draw the strip tofits intended true shape, said position.

LEON n-umnm. 

